(1) Field of the Invention
The invention generally relates to monitoring the performance of microscopes. More particularly, the invention relates to new structures for creating diagnostic images and diagnostic information to monitor changes in illumination that may degrade over time, overall microscope performance and other microscope properties
(2) Description of the Related Art
U.S. Pat. No. 8,314,931 Method and System for Standardizing Microscope Instruments by Christiansen et al, issued on Nov. 20, 2012, describes a reflective calibration surface at the bottom of a modified microscope fluorescence filter cube. The system of the '931 Patent reflects the light emitted from the dichroic mirror back into the cube to be viewed by the microscope image acquisition system. While the Christiansen system does provide information regarding light intensity, the resulting diffusion from this technique obscures important detail.
Microscopes are well known in the prior art. The current state of the art in clinical practice and biological research favors epi illumination microscopy wherein an object is illuminated though the same objective being used to image or view that object. Most applications of epi illumination involve at least two optical axes, one for illumination and one for observation. When multiple optical axes are involved, a reflecting device such as a mirror, beam splitter, or fluorescence filter cube is used at the junction of these axes to appropriately join the axes together. The strategic location of this optical axes junction provides the opportunity for the replacement of these junction components with a newly designed diagnostic cube that will directly relay a diagnostic image of the epi illumination transmitting through one optical axis to an observation device, such as a camera or binocular in the added optical axis. The viewed object may be illuminated by various light sources that are often diffused, obfuscated, filtered and otherwise modified resulting in a diminished or uneven illumination of the object.
To facilitate standardized or accurate observations of an objects, the illumination of a microscope must remain uniform and consistent to avoid misinformation. While the prior art provides useful illumination via the Kohler illuminated epi illumination system as described below, the prior art fails to comprehensively address the source of the performance declines of modern microscopes.
Modern microscopes are often illuminated with several components that may be responsible for illumination performance problems. These components may include but are not limited to LEDs, lasers, light bulbs, fiber optic cables, liquid light guides, liquid light guide couplers, as well as beam steering and beam focusing optics. Such problems may be non-linear, temporal, subtle or dramatic even to a trained professional, revealing profound shortfalls with the prior art.
The overall benefits of the prior art epi illumination light path are widely utilized in the microscope industry, but the design is flawed with respect to monitoring changes in performance of modern microscopes. For example, the conjugate planes described in a Kohler epi illumination system, demonstrate the visibility of the epi illuminated light source in the aperture or illumination planes of the microscope. State of the art techniques that are built into a microscope for measuring the performance of an epi illuminated light source do not address the light source as seen in the illumination plane and therefore lack the ability to detect significant misalignments or changes that may occur with the illumination source components.
While the prior art of Kohler epi illumination is inherently flawed in the area of detecting changes in illumination, light sources (often used in Kohler systems) are especially prone to performance declines. Moreover, other components, which include laser combiners, fiber optics cables, fiber optic couplers, liquid light guides and liquid light guide couplers also underperform or degrade with handling and use over time. Fiber optic cables, coupler interfaces, liquid light guides and liquid light guide couplers are easily compromised. Alignment issues also will affect a microscope's performance. If a bulb is misaligned or a liquid light guide is not properly positioned, the performance of a fluorescence microscope will be degraded. If the fiber optic cable of a laser based illumination source is compromised, that laser based microscope will underperform. Unintended obstructions to a light source will compromise the performance of microscope and are difficult to diagnose if the user is unable to see and monitor performance.